People have been predicting the death of text messaging for decades.
Or, more accurately, they love SMS but hate paying the fees that
telecoms charge for delivering messages, and they have been hoping
that one of the many competitors (AOL instant messaging, Skype,
Twitter, etc.) will succeed in displacing it.

All this time it’s been no contest, and the reason is simple: greed.
Say what you will about the telecom industry, text messaging works. A
phone can send a text to any other phone, regardless of telecom
provider. None of the competitors has been willing to cooperate with
any other; they are all building walled gardens, trying to shut out
their rivals. This approach can cut into telecom profits, but it will
never make SMS less than indispensible.

WebRTC, which standardizes
video chat in web browsers, is the first technology I’ve seen that has
a chance at killing SMS.

WebRTC is not actually a technological advance. It takes SIP, mutates
it a bit, and embeds it in a web browser (starting with Chrome and now
Firefox). I don’t like
SIP, and WebRTC is
barely an improvement from a technical point of view (I think
Microsoft’s
approach is
better).

But its non-technical advantages are going to make all the
difference:

Implementation

Google is pouring resources into WebRTC, and they are competent. It
would be possible to make a very good SIP client with comparable
effort, but somehow no one has made that happen. Google’s WebRTC
implementation is better than 99% of SIP clients on latency,
bandwidth, audio and video quality, and firewall/NAT traversal, and it
supports multi-party chat out of the box.

Compatibility

Google is committed to interoperability, but their approach is
different from the IETF’s with SIP. The IETF tries to get multiple
implementations running and interoperating while they develop a
standard; Google has worked first on their implementation, and only
pursued interoperability late in the game. The IETF strategy resulted
in a design-by-committee spec, whereas the Google strategy started
with a good implementation and is leading to a (hopefully better)
spec. Based on the quality of clients and servers, this has been a
decisive win for Google.

Ubiquity

Everyone has a web browser, so, eventually, everyone will have a
WebRTC client.

Building block strategy

WebRTC is infrastructure. It does not provide a video chat service;
it provides peer-to-peer media and data connections that can be used
to build video chat services and clients. Moreover, the barrier to
entry is low: any web developer can build a client and server.

This is really the key with regards to SMS. Yes, Google and Facebook
can easily build walled-garden chat services with WebRTC, but so can
everyone else, and it’s just as easy to build an open chat service.
And only an open chat service can kill SMS.